Instructions: Start the test after 20 minutes of consumption. After pressing the switch, "Heat" will appear. After 10 seconds of warming up, "Hit" is displayed. Blow out within 10 seconds of the countdown and blow out with moderate force for 3-5 seconds. Awaiting results. A warning sign will appear if the ethanol level is 0.02% BAC (0.2g/L) - 0.05% BAC (0.5g/L). If ethanol accuracy is greater than or equal to 0.05% BAC (0.5 g/L), a Danger warning sign will appear and a rapid tone will sound. 10 seconds after the announcement of the results, the ethanol detector automatically stops. For the test to be accurate, it is recommended to repeat the test 2-3 times. Material: ABS. Precision : -0.01~+0.02% BAC. Blowing time: within 10 seconds. Cut : 11 x 3 x 7cm/4.3 x 1.2 x 2.8 inch. Feed : 2 AA alkaline batteries (not included)